level 10
$ sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
出现错误
Executing: /tmp/apt-key-gpghome.ZqIcif1Acm/gpg.1.sh --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EFgpg: failed to start the dirmngr '/usr/bin/dirmngr': No such file or directorygpg: connecting dirmngr at '/tmp/apt-key-gpghome.ZqIcif1Acm/S.dirmngr' failed: No such file or directorygpg: keyserver receive failed: No dirmngr